The present invention relates to animal and human implantable physiological and/or chemical sensors, tissue stimulating electrodes, and/or implantable fluid delivery/receiving systems. More particularly, the invention relates to a replaceable catheter system for such sensors, electrodes and fluid delivery/receiving systems.
U.S. Pat. Nos. 4,484,987; 4,650,547; 4,781,798; 4,627,906; 4,671,288; 4,703,756; 4,890,620; 5,190,041; 5,165,407; and 5,001,054 describe various forms of glucose sensing electrodes and systems for detecting variations in and levels of glucose in blood. These patents are incorporated herein by reference.
U.S. Pat. No. 4,373,527 describes an implantable programmable medication infusion system for injecting controlled quantities of a medication such as insulin to correct for fluctuations and stabilize the level of glucose within a human in response to control information stored within the implantable system. The '527 patent is incorporated herein by reference.
U.S. Pat. No. 4,494,950 describes a medication delivery system including a plurality of modules implantable within and/or wearable by a patient. In particular, an implanted glucose sensor generates and transmits information to one or more implanted modules or modules wearable by a patient. One of the implanted modules may comprise a medication infusion system responsive to the signals from the glucose sensor module for regulating the delivery of insulin to the patient. The '950 patent also describes a system wherein a glucose sensor is connected to the end of a needle inserted through the skin of the patient and connected by an electrical lead to an external signal processing module for telemetering data to an implanted module including a medication release system for dispensing controlled amounts of medication into the patient in response to the signals from the sensor. Being attached to the tip end of the needle, the glucose sensor may be readily replaced as needed. The '950 patent is incorporated herein by reference.
While the '950 patent describes a system in which a physiological sensor on a needle tip and located just under a patient's skin is readily replaceable, surgically implanted in vivo sensors and electrodes still require surgical removal with the associated expense and risks of infection to the patient.
Accordingly, there is a continuing need for a system that allows for the implanting of physiological sensors, and/or electrodes within the body of a human in areas where it is desired to sense a predetermined physiological activity, to receive a body fluid for analysis, or to stimulate tissue; and wherein the sensor, tube, and/or an electrode may be readily replaced without engaging in an extensive, expensive and risky surgical procedure. Also, for situations where the sensor, tube, or electrode may need to be replaced frequently, e.g. every six months, while the remainder of the system with which the sensor, tube or electrode is used may last for some time, e.g. several years, it is desirable that the system accommodate replacement of only the sensor, tube or electrode portion while leaving the balance of the support system intact. Further, there is a similar need for replaceability in implantable fluid dispensing and/or receiving systems wherein fluid delivery or receiving tubes may become clogged and require replacement. In such situations, it is desirable to provide a system which allows for the non-surgical replacement of the fluid delivery/receiving tubes from the implantable fluid dispenser, such as a drug pump. The present invention satisfies such needs.